Why doctors should be asking about your ‘skeletal age’
Professor of predictive medicine, Tuan Nguyen, says it’s never too early to think about your bone health. Photo / Getty Images
What is your skeletal age? And how is the state of your bones likely to affect your chances of a premature death? Those are questions scientists at the University of Technology Sydney think an ageing population needs to consider.
In a study of more than 1.6 million adults, they found a bone fracture is associated with a loss of one to seven years of life, depending on gender, age and fracture site. The risk is greatest for patients with a hip fracture, about a third of whom die within a year. On the basis of this and previous research, they are proposing the idea of skeletal age as a metric for assessing risk.
Project leader Tuan Nguyen, a professor of predictive medicine, says in cardiovascular medicine one way of understanding someone’s chance of having a heart attack or stroke is to measure their heart age. Similarly in respiratory medicine, lung age can be used as a tool to urge smokers to quit. So it made sense to apply the same approach to the bones.
“Various studies have shown fractures are associated with an increased risk of premature death, yet doctors don’t normally talk to their patients about that,” says Nguyen.
“It can mean people don’t take bone health seriously enough. They aren’t getting treatment or taking preventive measures, which puts them at risk of further fractures and mortality. We thought we should develop a tool to inform people about their risk.”
That tool, the Bonecheck calculator, is available free online at bonecheck.org and is intended for people aged 50 and above. The algorithm was developed by Nguyen’s team using data collected from five sources, including the Dubbo Osteoporosis Epidemiology Study.
They evaluated 50 potential risk factors, identifying five that were most significant and measurable: age, bone-mineral density, body weight, number of fractures occurring after age 50 and number of falls in the past 12 months. Ideally, users will have had a DEXA scan – a low dose X-ray to measure bone density.
“We aim to empower individuals to take preventive action,” says Nguyen.
“The tool is also designed for doctors so they have evidence-based information they can discuss with the patient and come up with a treatment plan.”
Bones might seem solid but they are in a constant state of flux. Cells called osteoclasts break down the bone’s matrix of collagen and minerals, releasing calcium into the bloodstream for reuse in other parts of the body. And another set of cells, osteoblasts, balance this out by forming new bone.